Fio 1.29
[fio.git] / fifo.h
CommitLineData
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1/*
2 * A simple FIFO implementation.
3 *
4 * Copyright (C) 2004 Stelian Pop <stelian@popies.net>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 */
21struct fifo {
22 unsigned char *buffer; /* the buffer holding the data */
23 unsigned int size; /* the size of the allocated buffer */
24 unsigned int in; /* data is added at offset (in % size) */
25 unsigned int out; /* data is extracted from off. (out % size) */
26};
27
28struct fifo *fifo_alloc(unsigned int);
29unsigned int fifo_put(struct fifo *, void *, unsigned int);
30unsigned int fifo_get(struct fifo *, void *, unsigned int);
38470f85 31void fifo_free(struct fifo *);
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32
33static inline unsigned int fifo_len(struct fifo *fifo)
34{
35 return fifo->in - fifo->out;
36}
37
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38static inline unsigned int fifo_room(struct fifo *fifo)
39{
40 return fifo->size - fifo->in + fifo->out;
41}
42
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43#define min(x,y) ({ \
44 typeof(x) _x = (x); \
45 typeof(y) _y = (y); \
46 (void) (&_x == &_y); \
47 _x < _y ? _x : _y; })
48
49#define max(x,y) ({ \
50 typeof(x) _x = (x); \
51 typeof(y) _y = (y); \
52 (void) (&_x == &_y); \
53 _x > _y ? _x : _y; })
54